1. Field of the Invention
This invention relates to a sensor device in which an IC module having a sensing portion at its top end is housed and fixed in a housing formed of a synthetic resin, and a pair of leads are connected at one end of them to the IC module in the housing.
2. Detailed Art Statement
The sensor device of the type described above has been already been known in, for example, Japanese Patent Laid-Open No. 2000-206130, in which an IC module is housed in a recess of a holder and a lid covering the containment recess in a state where the IC module is contained in the holder, and the holder and the lid are housed by a housing.
However, in the existent device described above, operation of attaching the lid to the holder to close the recess in the state where the IC module is contained in the recess is troublesome, and the structure for attaching the lid to the holder is also complicate.
This invention has been achieved in view of the situations, and it intends to provide a sensor device which can facilitate the assembling operation of the IC module, and which has a simplified structure for fixing and assembling the IC module.
For attaining the foregoing object, this invention provides a sensor device in which an IC module having a sensing portion at its top end is housed and fixed in a housing formed of a synthetic resin, and a pair of leads are connected at one end of them to the IC module in the housing,
the sensor device including a holder assembly comprising;
a first holder having a containment recess for containing the IC module while retaining the top end of the IC module, and an insert hole leading to the containment recess for allowing the IC module to be inserted to the containment recess, and
a second holder having a partition wall to be disposed between the pair of leads connected to the rear end of the IC module, inserted in the insert hole of the first holder, and retaining the rear part of the IC module in cooperation with the first holder,
the IC module in a state contained in the containment recess and the holder assembly being enclosed in the housing.
In accordance with the constitution described above, the holder assembly can be assembled by inserting the IC module connected at the rear end thereof with the pair of leads and the second holder having the partition wall being put between both of the leads through the insert hole into the first holder, thereby retaining the top end of the IC module contained in the containment recess by the first holder and retaining the rear part of the IC module by the first holder and the second holder that is inserted into the insert hole while preventing the pair of leads from being in contact with each other. This can facilitate the operation of assembling the IC module to the holder assembly, as well as simplify the structure of assembling the second holder to the first holder. Further, since the IC module in the state contained in the containment recess and the holder assembly are enclosed in the housing, this can facilitate manufacture of the sensor device in which the IC module is housed and fixed in the housing with the sensing portion being located to the top end of the housing and the pair of leads are connected at one end of them with the IC module in the housing.
Further, in a preferred embodiment of the invention having the constitution described above, protrusions that are melt upon contact with a molten resin charged in a molding apparatus for forming the housing are formed to the first holder made of a synthetic resin so as to surround the opening end of the containment recess and the rear opening end of the insert hole over the entire periphery thereof, respectively, and the positioning abutments in direct contact with the molds of the molding apparatus are disposed to the surface of the first holder at positions for putting the protrusions between the opening end of the containment recess and the rear opening end of the insert hole so as to position and fix the holder assembly in the molding apparatus.
With the constitution of this preferred embodiment, even when water should intrude to the joined faces between the first holder and the housing, since the periphery at the opening end of the containment recess and the rear opening end of the insert hole are in an intimate contact with the housing by the molten protrusions of the first holder, intrusion of water toward the IC module in the containment recess can be reliably prevented.